Column/Bar Chart

Use it to...

Do not Use it for...

Comparisons: Better use one-dimensional scatterplots, because these are
not dominated by bars or columns.

Larger data sets: Use line charts.

Selecting Bars or Columns

Use analogy as a selection criterion, if applicable; when in doubt, use
columns

Use a horizontal bar chart if the labels are too long to fit under the
columns

Variants

Multiple Column/Bar Chart: Use it to present data rows for several
variables

Side-by-Side Chart: Use it to (1) show contrasting trends between
levels of an independent variable, (2) if comparisons between individual
pairs of values are most important; do not use for more than two independent
variables

Figure 2: Multiple column chart (left), side-by-side
chart (right)

Segmented Column/Bar Chart

Other Names: Divided or stacked column/bar chart

Figure 3: Segmented column chart (relative values)

Use it to...

Present a part-whole relation over time (with accurate impression, see
below)

Show proportional relationships over time

Display wholes which are levels on a nominal scale

Segmented column/bar charts are more accurate than pie chart, because distances
can be more accurately estimated than areas.

Scatterplot

Variants

One-dimensional scatterplot: Data point are drawn above a baseline
(as in column/bar charts). Here the data points are not connected but remain
isolated data points.

Two-dimensional scatter plot: Shows correlation between two data
sets. This chart type has two dependent variables: One is plotted along the
X axis, the other along the Y axis; the independent variable is the intersection
of both dependent variables, realized as a data point in the diagram.

Use it to...

Show measurements over time (one-dimensional scatterplot)

Convey an overall impression of the relation between two variables (Two-dimensional
scatterplot)